Devices for conveying a fine-particle medium, for instance a medium which is in the form of a granulate or in powder form, are well known from the prior art.
A market-standard form of delivery of hotmelt for packaging applications is granulate. This can be fed from a receptacle to a further processing unit, for instance a melting unit. Granulates of such a type are inclined to wedge in a storage tank or intermediate storage tank, to clog, to form cavities or, depending on their chemical formulation, to stick together or bond together. Consequently, the onward feed of the granulate into a connected further processing unit is interrupted or disturbed.
A device of the type stated in the introduction is known from DE 20 2010 006 010 U1. This has a suction apparatus, disposed within the flexible receptacle, with vibration unit. The vibration unit consists of a plurality of vibration elements. These achieve a loosening effect, in the region of the vibration unit, of the medium received by the receptacle. According to a first variant, the vibration unit is disposed only in a central region of the receptacle and is therefore of compact and structurally relatively simple design. As a result of this configuration and arrangement of the vibration unit, clogging of the medium in the region of the side walls of the receptacle cannot be prevented. According to a second variant, it is provided that the vibration unit extends over the entire cross section of the receptacle. Since the vibration unit reaches to the side walls of the receptacle, this design prevents clogging to be attained over the entire cross section of the receptacle. However, the structural complexity for the vibration unit is very high. Because of its size, moreover, the vibration unit has a high weight, so that the total mass of the mobile suction apparatus with vibration unit is very high.
In EP 2 612 817 A1, a flexible receptacle having a material discharge funnel disposed in the region of the base of the receptacle is known. The funnel is provided with lateral receiving apparatuses for transmitting a vibration generated outside the funnel into the interior of the receptacle. The material of the funnel is selected such that a phase shift or amplitude shift between internal and external vibration is achieved, which shift prevents clogging/adhesion of the fine-particle medium on/to the funnel.
In EP 1 544 132 A2, a receptacle for receiving pellets or similarly sized items is described, wherein the storage receptacle is provided with movable, plate-like side walls. Through mechanical adjustment of the pitch of the side walls by means of a winch and the therewith associated volume reduction of the storage receptacle, the material delivery into a discharge apparatus, for example a worm, is ensured. During emptying of the receptacle prior to refilling, the receptacle volume must be mechanically enlarged again by resetting of the side walls.
From U.S. Pat. No. 2,829,803, a receptacle having mechanically adjustable side walls is likewise known.